Initial import.

vendor/guzzle/plugin-cache/Guzzle/Plugin/Cache/CacheKeyProviderInterface.php

@@ -0,0 +1,11 @@
+<?php
+
+namespace Guzzle\Plugin\Cache;
+
+\Guzzle\Common\Version::warn('Guzzle\Plugin\Cache\CacheKeyProviderInterface is no longer used');
+
+/**
+ * @deprecated This is no longer used
+ * @codeCoverageIgnore
+ */
+interface CacheKeyProviderInterface {}

vendor/guzzle/plugin-cache/Guzzle/Plugin/Cache/CachePlugin.php

@@ -0,0 +1,353 @@
+<?php
+
+namespace Guzzle\Plugin\Cache;
+
+use Guzzle\Cache\CacheAdapterFactory;
+use Guzzle\Cache\CacheAdapterInterface;
+use Guzzle\Common\Event;
+use Guzzle\Common\Exception\InvalidArgumentException;
+use Guzzle\Common\Version;
+use Guzzle\Http\Message\RequestInterface;
+use Guzzle\Http\Message\Response;
+use Guzzle\Cache\DoctrineCacheAdapter;
+use Guzzle\Http\Exception\CurlException;
+use Doctrine\Common\Cache\ArrayCache;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+
+/**
+ * Plugin to enable the caching of GET and HEAD requests.  Caching can be done on all requests passing through this
+ * plugin or only after retrieving resources with cacheable response headers.
+ *
+ * This is a simple implementation of RFC 2616 and should be considered a private transparent proxy cache, meaning
+ * authorization and private data can be cached.
+ *
+ * It also implements RFC 5861's `stale-if-error` Cache-Control extension, allowing stale cache responses to be used
+ * when an error is encountered (such as a `500 Internal Server Error` or DNS failure).
+ */
+class CachePlugin implements EventSubscriberInterface
+{
+    /** @var RevalidationInterface Cache revalidation strategy */
+    protected $revalidation;
+
+    /** @var CanCacheStrategyInterface Object used to determine if a request can be cached */
+    protected $canCache;
+
+    /** @var CacheStorageInterface $cache Object used to cache responses */
+    protected $storage;
+
+    /** @var bool */
+    protected $autoPurge;
+
+    /**
+     * @param array|CacheAdapterInterface|CacheStorageInterface $options Array of options for the cache plugin,
+     *     cache adapter, or cache storage object.
+     *     - CacheStorageInterface storage:      Adapter used to cache responses
+     *     - RevalidationInterface revalidation: Cache revalidation strategy
+     *     - CanCacheInterface     can_cache:    Object used to determine if a request can be cached
+     *     - bool                  auto_purge    Set to true to automatically PURGE resources when non-idempotent
+     *                                           requests are sent to a resource. Defaults to false.
+     * @throws InvalidArgumentException if no cache is provided and Doctrine cache is not installed
+     */
+    public function __construct($options = null)
+    {
+        if (!is_array($options)) {
+            if ($options instanceof CacheAdapterInterface) {
+                $options = array('storage' => new DefaultCacheStorage($options));
+            } elseif ($options instanceof CacheStorageInterface) {
+                $options = array('storage' => $options);
+            } elseif ($options) {
+                $options = array('storage' => new DefaultCacheStorage(CacheAdapterFactory::fromCache($options)));
+            } elseif (!class_exists('Doctrine\Common\Cache\ArrayCache')) {
+                // @codeCoverageIgnoreStart
+                throw new InvalidArgumentException('No cache was provided and Doctrine is not installed');
+                // @codeCoverageIgnoreEnd
+            }
+        }
+
+        $this->autoPurge = isset($options['auto_purge']) ? $options['auto_purge'] : false;
+
+        // Add a cache storage if a cache adapter was provided
+        $this->storage = isset($options['storage'])
+            ? $options['storage']
+            : new DefaultCacheStorage(new DoctrineCacheAdapter(new ArrayCache()));
+
+        if (!isset($options['can_cache'])) {
+            $this->canCache = new DefaultCanCacheStrategy();
+        } else {
+            $this->canCache = is_callable($options['can_cache'])
+                ? new CallbackCanCacheStrategy($options['can_cache'])
+                : $options['can_cache'];
+        }
+
+        // Use the provided revalidation strategy or the default
+        $this->revalidation = isset($options['revalidation'])
+            ? $options['revalidation']
+            : new DefaultRevalidation($this->storage, $this->canCache);
+    }
+
+    public static function getSubscribedEvents()
+    {
+        return array(
+            'request.before_send' => array('onRequestBeforeSend', -255),
+            'request.sent'        => array('onRequestSent', 255),
+            'request.error'       => array('onRequestError', 0),
+            'request.exception'   => array('onRequestException', 0),
+        );
+    }
+
+    /**
+     * Check if a response in cache will satisfy the request before sending
+     *
+     * @param Event $event
+     */
+    public function onRequestBeforeSend(Event $event)
+    {
+        $request = $event['request'];
+        $request->addHeader('Via', sprintf('%s GuzzleCache/%s', $request->getProtocolVersion(), Version::VERSION));
+
+        if (!$this->canCache->canCacheRequest($request)) {
+            switch ($request->getMethod()) {
+                case 'PURGE':
+                    $this->purge($request);
+                    $request->setResponse(new Response(200, array(), 'purged'));
+                    break;
+                case 'PUT':
+                case 'POST':
+                case 'DELETE':
+                case 'PATCH':
+                    if ($this->autoPurge) {
+                        $this->purge($request);
+                    }
+            }
+            return;
+        }
+
+        if ($response = $this->storage->fetch($request)) {
+            $params = $request->getParams();
+            $params['cache.lookup'] = true;
+            $response->setHeader(
+                'Age',
+                time() - strtotime($response->getDate() ? : $response->getLastModified() ?: 'now')
+            );
+            // Validate that the response satisfies the request
+            if ($this->canResponseSatisfyRequest($request, $response)) {
+                if (!isset($params['cache.hit'])) {
+                    $params['cache.hit'] = true;
+                }
+                $request->setResponse($response);
+            }
+        }
+    }
+
+    /**
+     * If possible, store a response in cache after sending
+     *
+     * @param Event $event
+     */
+    public function onRequestSent(Event $event)
+    {
+        $request = $event['request'];
+        $response = $event['response'];
+
+        if ($request->getParams()->get('cache.hit') === null &&
+            $this->canCache->canCacheRequest($request) &&
+            $this->canCache->canCacheResponse($response)
+        ) {
+            $this->storage->cache($request, $response);
+        }
+
+        $this->addResponseHeaders($request, $response);
+    }
+
+    /**
+     * If possible, return a cache response on an error
+     *
+     * @param Event $event
+     */
+    public function onRequestError(Event $event)
+    {
+        $request = $event['request'];
+
+        if (!$this->canCache->canCacheRequest($request)) {
+            return;
+        }
+
+        if ($response = $this->storage->fetch($request)) {
+            $response->setHeader(
+                'Age',
+                time() - strtotime($response->getLastModified() ? : $response->getDate() ?: 'now')
+            );
+
+            if ($this->canResponseSatisfyFailedRequest($request, $response)) {
+                $request->getParams()->set('cache.hit', 'error');
+                $this->addResponseHeaders($request, $response);
+                $event['response'] = $response;
+                $event->stopPropagation();
+            }
+        }
+    }
+
+    /**
+     * If possible, set a cache response on a cURL exception
+     *
+     * @param Event $event
+     *
+     * @return null
+     */
+    public function onRequestException(Event $event)
+    {
+        if (!$event['exception'] instanceof CurlException) {
+            return;
+        }
+
+        $request = $event['request'];
+        if (!$this->canCache->canCacheRequest($request)) {
+            return;
+        }
+
+        if ($response = $this->storage->fetch($request)) {
+            $response->setHeader('Age', time() - strtotime($response->getDate() ? : 'now'));
+            if (!$this->canResponseSatisfyFailedRequest($request, $response)) {
+                return;
+            }
+            $request->getParams()->set('cache.hit', 'error');
+            $request->setResponse($response);
+            $this->addResponseHeaders($request, $response);
+            $event->stopPropagation();
+        }
+    }
+
+    /**
+     * Check if a cache response satisfies a request's caching constraints
+     *
+     * @param RequestInterface $request  Request to validate
+     * @param Response         $response Response to validate
+     *
+     * @return bool
+     */
+    public function canResponseSatisfyRequest(RequestInterface $request, Response $response)
+    {
+        $responseAge = $response->calculateAge();
+        $reqc = $request->getHeader('Cache-Control');
+        $resc = $response->getHeader('Cache-Control');
+
+        // Check the request's max-age header against the age of the response
+        if ($reqc && $reqc->hasDirective('max-age') &&
+            $responseAge > $reqc->getDirective('max-age')) {
+            return false;
+        }
+
+        // Check the response's max-age header
+        if ($response->isFresh() === false) {
+            $maxStale = $reqc ? $reqc->getDirective('max-stale') : null;
+            if (null !== $maxStale) {
+                if ($maxStale !== true && $response->getFreshness() < (-1 * $maxStale)) {
+                    return false;
+                }
+            } elseif ($resc && $resc->hasDirective('max-age')
+                && $responseAge > $resc->getDirective('max-age')
+            ) {
+                return false;
+            }
+        }
+
+        if ($this->revalidation->shouldRevalidate($request, $response)) {
+            try {
+                return $this->revalidation->revalidate($request, $response);
+            } catch (CurlException $e) {
+                $request->getParams()->set('cache.hit', 'error');
+                return $this->canResponseSatisfyFailedRequest($request, $response);
+            }
+        }
+
+        return true;
+    }
+
+    /**
+     * Check if a cache response satisfies a failed request's caching constraints
+     *
+     * @param RequestInterface $request  Request to validate
+     * @param Response         $response Response to validate
+     *
+     * @return bool
+     */
+    public function canResponseSatisfyFailedRequest(RequestInterface $request, Response $response)
+    {
+        $reqc = $request->getHeader('Cache-Control');
+        $resc = $response->getHeader('Cache-Control');
+        $requestStaleIfError = $reqc ? $reqc->getDirective('stale-if-error') : null;
+        $responseStaleIfError = $resc ? $resc->getDirective('stale-if-error') : null;
+
+        if (!$requestStaleIfError && !$responseStaleIfError) {
+            return false;
+        }
+
+        if (is_numeric($requestStaleIfError) && $response->getAge() - $response->getMaxAge() > $requestStaleIfError) {
+            return false;
+        }
+
+        if (is_numeric($responseStaleIfError) && $response->getAge() - $response->getMaxAge() > $responseStaleIfError) {
+            return false;
+        }
+
+        return true;
+    }
+
+    /**
+     * Purge all cache entries for a given URL
+     *
+     * @param string $url URL to purge
+     */
+    public function purge($url)
+    {
+        // BC compatibility with previous version that accepted a Request object
+        $url = $url instanceof RequestInterface ? $url->getUrl() : $url;
+        $this->storage->purge($url);
+    }
+
+    /**
+     * Add the plugin's headers to a response
+     *
+     * @param RequestInterface $request  Request
+     * @param Response         $response Response to add headers to
+     */
+    protected function addResponseHeaders(RequestInterface $request, Response $response)
+    {
+        $params = $request->getParams();
+        $response->setHeader('Via', sprintf('%s GuzzleCache/%s', $request->getProtocolVersion(), Version::VERSION));
+
+        $lookup = ($params['cache.lookup'] === true ? 'HIT' : 'MISS') . ' from GuzzleCache';
+        if ($header = $response->getHeader('X-Cache-Lookup')) {
+            // Don't add duplicates
+            $values = $header->toArray();
+            $values[] = $lookup;
+            $response->setHeader('X-Cache-Lookup', array_unique($values));
+        } else {
+            $response->setHeader('X-Cache-Lookup', $lookup);
+        }
+
+        if ($params['cache.hit'] === true) {
+            $xcache = 'HIT from GuzzleCache';
+        } elseif ($params['cache.hit'] == 'error') {
+            $xcache = 'HIT_ERROR from GuzzleCache';
+        } else {
+            $xcache = 'MISS from GuzzleCache';
+        }
+
+        if ($header = $response->getHeader('X-Cache')) {
+            // Don't add duplicates
+            $values = $header->toArray();
+            $values[] = $xcache;
+            $response->setHeader('X-Cache', array_unique($values));
+        } else {
+            $response->setHeader('X-Cache', $xcache);
+        }
+
+        if ($response->isFresh() === false) {
+            $response->addHeader('Warning', sprintf('110 GuzzleCache/%s "Response is stale"', Version::VERSION));
+            if ($params['cache.hit'] === 'error') {
+                $response->addHeader('Warning', sprintf('111 GuzzleCache/%s "Revalidation failed"', Version::VERSION));
+            }
+        }
+    }
+}

vendor/guzzle/plugin-cache/Guzzle/Plugin/Cache/CacheStorageInterface.php

@@ -0,0 +1,43 @@
+<?php
+
+namespace Guzzle\Plugin\Cache;
+
+use Guzzle\Http\Message\RequestInterface;
+use Guzzle\Http\Message\Response;
+
+/**
+ * Interface used to cache HTTP requests
+ */
+interface CacheStorageInterface
+{
+    /**
+     * Get a Response from the cache for a request
+     *
+     * @param RequestInterface $request
+     *
+     * @return null|Response
+     */
+    public function fetch(RequestInterface $request);
+
+    /**
+     * Cache an HTTP request
+     *
+     * @param RequestInterface $request  Request being cached
+     * @param Response         $response Response to cache
+     */
+    public function cache(RequestInterface $request, Response $response);
+
+    /**
+     * Deletes cache entries that match a request
+     *
+     * @param RequestInterface $request Request to delete from cache
+     */
+    public function delete(RequestInterface $request);
+
+    /**
+     * Purge all cache entries for a given URL
+     *
+     * @param string $url
+     */
+    public function purge($url);
+}

vendor/guzzle/plugin-cache/Guzzle/Plugin/Cache/CallbackCanCacheStrategy.php

@@ -0,0 +1,53 @@
+<?php
+
+namespace Guzzle\Plugin\Cache;
+
+use Guzzle\Common\Exception\InvalidArgumentException;
+use Guzzle\Http\Message\RequestInterface;
+use Guzzle\Http\Message\Response;
+
+/**
+ * Determines if a request can be cached using a callback
+ */
+class CallbackCanCacheStrategy extends DefaultCanCacheStrategy
+{
+    /** @var callable Callback for request */
+    protected $requestCallback;
+
+    /** @var callable Callback for response */
+    protected $responseCallback;
+
+    /**
+     * @param \Closure|array|mixed $requestCallback  Callable method to invoke for requests
+     * @param \Closure|array|mixed $responseCallback Callable method to invoke for responses
+     *
+     * @throws InvalidArgumentException
+     */
+    public function __construct($requestCallback = null, $responseCallback = null)
+    {
+        if ($requestCallback && !is_callable($requestCallback)) {
+            throw new InvalidArgumentException('Method must be callable');
+        }
+
+        if ($responseCallback && !is_callable($responseCallback)) {
+            throw new InvalidArgumentException('Method must be callable');
+        }
+
+        $this->requestCallback = $requestCallback;
+        $this->responseCallback = $responseCallback;
+    }
+
+    public function canCacheRequest(RequestInterface $request)
+    {
+        return $this->requestCallback
+            ? call_user_func($this->requestCallback, $request)
+            : parent::canCacheRequest($request);
+    }
+
+    public function canCacheResponse(Response $response)
+    {
+        return $this->responseCallback
+            ? call_user_func($this->responseCallback, $response)
+            : parent::canCacheResponse($response);
+    }
+}

vendor/guzzle/plugin-cache/Guzzle/Plugin/Cache/CanCacheStrategyInterface.php

@@ -0,0 +1,30 @@
+<?php
+
+namespace Guzzle\Plugin\Cache;
+
+use Guzzle\Http\Message\RequestInterface;
+use Guzzle\Http\Message\Response;
+
+/**
+ * Strategy used to determine if a request can be cached
+ */
+interface CanCacheStrategyInterface
+{
+    /**
+     * Determine if a request can be cached
+     *
+     * @param RequestInterface $request Request to determine
+     *
+     * @return bool
+     */
+    public function canCacheRequest(RequestInterface $request);
+
+    /**
+     * Determine if a response can be cached
+     *
+     * @param Response $response Response to determine
+     *
+     * @return bool
+     */
+    public function canCacheResponse(Response $response);
+}

vendor/guzzle/plugin-cache/Guzzle/Plugin/Cache/DefaultCacheKeyProvider.php

@@ -0,0 +1,46 @@
+<?php
+
+namespace Guzzle\Plugin\Cache;
+
+use Guzzle\Http\Message\RequestInterface;
+
+\Guzzle\Common\Version::warn('Guzzle\Plugin\Cache\DefaultCacheKeyProvider is no longer used');
+
+/**
+ * @deprecated This class is no longer used
+ * @codeCoverageIgnore
+ */
+class DefaultCacheKeyProvider implements CacheKeyProviderInterface
+{
+    public function getCacheKey(RequestInterface $request)
+    {
+        // See if the key has already been calculated
+        $key = $request->getParams()->get(self::CACHE_KEY);
+
+        if (!$key) {
+
+            $cloned = clone $request;
+            $cloned->removeHeader('Cache-Control');
+
+            // Check to see how and if the key should be filtered
+            foreach (explode(';', $request->getParams()->get(self::CACHE_KEY_FILTER)) as $part) {
+                $pieces = array_map('trim', explode('=', $part));
+                if (isset($pieces[1])) {
+                    foreach (array_map('trim', explode(',', $pieces[1])) as $remove) {
+                        if ($pieces[0] == 'header') {
+                            $cloned->removeHeader($remove);
+                        } elseif ($pieces[0] == 'query') {
+                            $cloned->getQuery()->remove($remove);
+                        }
+                    }
+                }
+            }
+
+            $raw = (string) $cloned;
+            $key = 'GZ' . md5($raw);
+            $request->getParams()->set(self::CACHE_KEY, $key)->set(self::CACHE_KEY_RAW, $raw);
+        }
+
+        return $key;
+    }
+}

vendor/guzzle/plugin-cache/Guzzle/Plugin/Cache/DefaultCacheStorage.php

@@ -0,0 +1,251 @@
+<?php
+
+namespace Guzzle\Plugin\Cache;
+
+use Guzzle\Cache\CacheAdapterFactory;
+use Guzzle\Cache\CacheAdapterInterface;
+use Guzzle\Http\EntityBodyInterface;
+use Guzzle\Http\Message\MessageInterface;
+use Guzzle\Http\Message\Request;
+use Guzzle\Http\Message\RequestInterface;
+use Guzzle\Http\Message\Response;
+
+/**
+ * Default cache storage implementation
+ */
+class DefaultCacheStorage implements CacheStorageInterface
+{
+    /** @var string */
+    protected $keyPrefix;
+
+    /** @var CacheAdapterInterface Cache used to store cache data */
+    protected $cache;
+
+    /** @var int Default cache TTL */
+    protected $defaultTtl;
+
+    /**
+     * @param mixed  $cache      Cache used to store cache data
+     * @param string $keyPrefix  Provide an optional key prefix to prefix on all cache keys
+     * @param int    $defaultTtl Default cache TTL
+     */
+    public function __construct($cache, $keyPrefix = '', $defaultTtl = 3600)
+    {
+        $this->cache = CacheAdapterFactory::fromCache($cache);
+        $this->defaultTtl = $defaultTtl;
+        $this->keyPrefix = $keyPrefix;
+    }
+
+    public function cache(RequestInterface $request, Response $response)
+    {
+        $currentTime = time();
+        $ttl = $request->getParams()->get('cache.override_ttl') ?: $response->getMaxAge() ?: $this->defaultTtl;
+
+        if ($cacheControl = $response->getHeader('Cache-Control')) {
+            $stale = $cacheControl->getDirective('stale-if-error');
+            $ttl += $stale == true ? $ttl : $stale;
+        }
+
+        // Determine which manifest key should be used
+        $key = $this->getCacheKey($request);
+        $persistedRequest = $this->persistHeaders($request);
+        $entries = array();
+
+        if ($manifest = $this->cache->fetch($key)) {
+            // Determine which cache entries should still be in the cache
+            $vary = $response->getVary();
+            foreach (unserialize($manifest) as $entry) {
+                // Check if the entry is expired
+                if ($entry[4] < $currentTime) {
+                    continue;
+                }
+                $entry[1]['vary'] = isset($entry[1]['vary']) ? $entry[1]['vary'] : '';
+                if ($vary != $entry[1]['vary'] || !$this->requestsMatch($vary, $entry[0], $persistedRequest)) {
+                    $entries[] = $entry;
+                }
+            }
+        }
+
+        // Persist the response body if needed
+        $bodyDigest = null;
+        if ($response->getBody() && $response->getBody()->getContentLength() > 0) {
+            $bodyDigest = $this->getBodyKey($request->getUrl(), $response->getBody());
+            $this->cache->save($bodyDigest, (string) $response->getBody(), $ttl);
+        }
+
+        array_unshift($entries, array(
+            $persistedRequest,
+            $this->persistHeaders($response),
+            $response->getStatusCode(),
+            $bodyDigest,
+            $currentTime + $ttl
+        ));
+
+        $this->cache->save($key, serialize($entries));
+    }
+
+    public function delete(RequestInterface $request)
+    {
+        $key = $this->getCacheKey($request);
+        if ($entries = $this->cache->fetch($key)) {
+            // Delete each cached body
+            foreach (unserialize($entries) as $entry) {
+                if ($entry[3]) {
+                    $this->cache->delete($entry[3]);
+                }
+            }
+            $this->cache->delete($key);
+        }
+    }
+
+    public function purge($url)
+    {
+        foreach (array('GET', 'HEAD', 'POST', 'PUT', 'DELETE') as $method) {
+            $this->delete(new Request($method, $url));
+        }
+    }
+
+    public function fetch(RequestInterface $request)
+    {
+        $key = $this->getCacheKey($request);
+        if (!($entries = $this->cache->fetch($key))) {
+            return null;
+        }
+
+        $match = null;
+        $headers = $this->persistHeaders($request);
+        $entries = unserialize($entries);
+        foreach ($entries as $index => $entry) {
+            if ($this->requestsMatch(isset($entry[1]['vary']) ? $entry[1]['vary'] : '', $headers, $entry[0])) {
+                $match = $entry;
+                break;
+            }
+        }
+
+        if (!$match) {
+            return null;
+        }
+
+        // Ensure that the response is not expired
+        $response = null;
+        if ($match[4] < time()) {
+            $response = -1;
+        } else {
+            $response = new Response($match[2], $match[1]);
+            if ($match[3]) {
+                if ($body = $this->cache->fetch($match[3])) {
+                    $response->setBody($body);
+                } else {
+                    // The response is not valid because the body was somehow deleted
+                    $response = -1;
+                }
+            }
+        }
+
+        if ($response === -1) {
+            // Remove the entry from the metadata and update the cache
+            unset($entries[$index]);
+            if ($entries) {
+                $this->cache->save($key, serialize($entries));
+            } else {
+                $this->cache->delete($key);
+            }
+            return null;
+        }
+
+        return $response;
+    }
+
+    /**
+     * Hash a request URL into a string that returns cache metadata
+     *
+     * @param RequestInterface $request
+     *
+     * @return string
+     */
+    protected function getCacheKey(RequestInterface $request)
+    {
+        // Allow cache.key_filter to trim down the URL cache key by removing generate query string values (e.g. auth)
+        if ($filter = $request->getParams()->get('cache.key_filter')) {
+            $url = $request->getUrl(true);
+            foreach (explode(',', $filter) as $remove) {
+                $url->getQuery()->remove(trim($remove));
+            }
+        } else {
+            $url = $request->getUrl();
+        }
+
+        return $this->keyPrefix . md5($request->getMethod() . ' ' . $url);
+    }
+
+    /**
+     * Create a cache key for a response's body
+     *
+     * @param string              $url  URL of the entry
+     * @param EntityBodyInterface $body Response body
+     *
+     * @return string
+     */
+    protected function getBodyKey($url, EntityBodyInterface $body)
+    {
+        return $this->keyPrefix . md5($url) . $body->getContentMd5();
+    }
+
+    /**
+     * Determines whether two Request HTTP header sets are non-varying
+     *
+     * @param string $vary Response vary header
+     * @param array  $r1   HTTP header array
+     * @param array  $r2   HTTP header array
+     *
+     * @return bool
+     */
+    private function requestsMatch($vary, $r1, $r2)
+    {
+        if ($vary) {
+            foreach (explode(',', $vary) as $header) {
+                $key = trim(strtolower($header));
+                $v1 = isset($r1[$key]) ? $r1[$key] : null;
+                $v2 = isset($r2[$key]) ? $r2[$key] : null;
+                if ($v1 !== $v2) {
+                    return false;
+                }
+            }
+        }
+
+        return true;
+    }
+
+    /**
+     * Creates an array of cacheable and normalized message headers
+     *
+     * @param MessageInterface $message
+     *
+     * @return array
+     */
+    private function persistHeaders(MessageInterface $message)
+    {
+        // Headers are excluded from the caching (see RFC 2616:13.5.1)
+        static $noCache = array(
+            'age' => true,
+            'connection' => true,
+            'keep-alive' => true,
+            'proxy-authenticate' => true,
+            'proxy-authorization' => true,
+            'te' => true,
+            'trailers' => true,
+            'transfer-encoding' => true,
+            'upgrade' => true,
+            'set-cookie' => true,
+            'set-cookie2' => true
+        );
+
+        // Clone the response to not destroy any necessary headers when caching
+        $headers = $message->getHeaders()->getAll();
+        $headers = array_diff_key($headers, $noCache);
+        // Cast the headers to a string
+        $headers = array_map(function ($h) { return (string) $h; }, $headers);
+
+        return $headers;
+    }
+}

vendor/guzzle/plugin-cache/Guzzle/Plugin/Cache/DefaultCanCacheStrategy.php

@@ -0,0 +1,32 @@
+<?php
+
+namespace Guzzle\Plugin\Cache;
+
+use Guzzle\Http\Message\RequestInterface;
+use Guzzle\Http\Message\Response;
+
+/**
+ * Default strategy used to determine of an HTTP request can be cached
+ */
+class DefaultCanCacheStrategy implements CanCacheStrategyInterface
+{
+    public function canCacheRequest(RequestInterface $request)
+    {
+        // Only GET and HEAD requests can be cached
+        if ($request->getMethod() != RequestInterface::GET && $request->getMethod() != RequestInterface::HEAD) {
+            return false;
+        }
+
+        // Never cache requests when using no-store
+        if ($request->hasHeader('Cache-Control') && $request->getHeader('Cache-Control')->hasDirective('no-store')) {
+            return false;
+        }
+
+        return true;
+    }
+
+    public function canCacheResponse(Response $response)
+    {
+        return $response->isSuccessful() && $response->canCache();
+    }
+}

vendor/guzzle/plugin-cache/Guzzle/Plugin/Cache/DefaultRevalidation.php

@@ -0,0 +1,174 @@
+<?php
+
+namespace Guzzle\Plugin\Cache;
+
+use Guzzle\Http\Message\RequestInterface;
+use Guzzle\Http\Message\Response;
+use Guzzle\Http\Exception\BadResponseException;
+
+/**
+ * Default revalidation strategy
+ */
+class DefaultRevalidation implements RevalidationInterface
+{
+    /** @var CacheStorageInterface Cache object storing cache data */
+    protected $storage;
+
+    /** @var CanCacheStrategyInterface */
+    protected $canCache;
+
+    /**
+     * @param CacheStorageInterface     $cache    Cache storage
+     * @param CanCacheStrategyInterface $canCache Determines if a message can be cached
+     */
+    public function __construct(CacheStorageInterface $cache, CanCacheStrategyInterface $canCache = null)
+    {
+        $this->storage = $cache;
+        $this->canCache = $canCache ?: new DefaultCanCacheStrategy();
+    }
+
+    public function revalidate(RequestInterface $request, Response $response)
+    {
+        try {
+            $revalidate = $this->createRevalidationRequest($request, $response);
+            $validateResponse = $revalidate->send();
+            if ($validateResponse->getStatusCode() == 200) {
+                return $this->handle200Response($request, $validateResponse);
+            } elseif ($validateResponse->getStatusCode() == 304) {
+                return $this->handle304Response($request, $validateResponse, $response);
+            }
+        } catch (BadResponseException $e) {
+            $this->handleBadResponse($e);
+        }
+
+        // Other exceptions encountered in the revalidation request are ignored
+        // in hopes that sending a request to the origin server will fix it
+        return false;
+    }
+
+    public function shouldRevalidate(RequestInterface $request, Response $response)
+    {
+        if ($request->getMethod() != RequestInterface::GET) {
+            return false;
+        }
+
+        $reqCache = $request->getHeader('Cache-Control');
+        $resCache = $response->getHeader('Cache-Control');
+
+        $revalidate = $request->getHeader('Pragma') == 'no-cache' ||
+            ($reqCache && ($reqCache->hasDirective('no-cache') || $reqCache->hasDirective('must-revalidate'))) ||
+            ($resCache && ($resCache->hasDirective('no-cache') || $resCache->hasDirective('must-revalidate')));
+
+        // Use the strong ETag validator if available and the response contains no Cache-Control directive
+        if (!$revalidate && !$resCache && $response->hasHeader('ETag')) {
+            $revalidate = true;
+        }
+
+        return $revalidate;
+    }
+
+    /**
+     * Handles a bad response when attempting to revalidate
+     *
+     * @param BadResponseException $e Exception encountered
+     *
+     * @throws BadResponseException
+     */
+    protected function handleBadResponse(BadResponseException $e)
+    {
+        // 404 errors mean the resource no longer exists, so remove from
+        // cache, and prevent an additional request by throwing the exception
+        if ($e->getResponse()->getStatusCode() == 404) {
+            $this->storage->delete($e->getRequest());
+            throw $e;
+        }
+    }
+
+    /**
+     * Creates a request to use for revalidation
+     *
+     * @param RequestInterface $request  Request
+     * @param Response         $response Response to revalidate
+     *
+     * @return RequestInterface returns a revalidation request
+     */
+    protected function createRevalidationRequest(RequestInterface $request, Response $response)
+    {
+        $revalidate = clone $request;
+        $revalidate->removeHeader('Pragma')->removeHeader('Cache-Control');
+
+        if ($response->getLastModified()) {
+            $revalidate->setHeader('If-Modified-Since', $response->getLastModified());
+        }
+
+        if ($response->getEtag()) {
+            $revalidate->setHeader('If-None-Match', $response->getEtag());
+        }
+
+        // Remove any cache plugins that might be on the request to prevent infinite recursive revalidations
+        $dispatcher = $revalidate->getEventDispatcher();
+        foreach ($dispatcher->getListeners() as $eventName => $listeners) {
+            foreach ($listeners as $listener) {
+                if (is_array($listener) && $listener[0] instanceof CachePlugin) {
+                    $dispatcher->removeListener($eventName, $listener);
+                }
+            }
+        }
+
+        return $revalidate;
+    }
+
+    /**
+     * Handles a 200 response response from revalidating. The server does not support validation, so use this response.
+     *
+     * @param RequestInterface $request          Request that was sent
+     * @param Response         $validateResponse Response received
+     *
+     * @return bool Returns true if valid, false if invalid
+     */
+    protected function handle200Response(RequestInterface $request, Response $validateResponse)
+    {
+        $request->setResponse($validateResponse);
+        if ($this->canCache->canCacheResponse($validateResponse)) {
+            $this->storage->cache($request, $validateResponse);
+        }
+
+        return false;
+    }
+
+    /**
+     * Handle a 304 response and ensure that it is still valid
+     *
+     * @param RequestInterface $request          Request that was sent
+     * @param Response         $validateResponse Response received
+     * @param Response         $response         Original cached response
+     *
+     * @return bool Returns true if valid, false if invalid
+     */
+    protected function handle304Response(RequestInterface $request, Response $validateResponse, Response $response)
+    {
+        static $replaceHeaders = array('Date', 'Expires', 'Cache-Control', 'ETag', 'Last-Modified');
+
+        // Make sure that this response has the same ETag
+        if ($validateResponse->getEtag() != $response->getEtag()) {
+            return false;
+        }
+
+        // Replace cached headers with any of these headers from the
+        // origin server that might be more up to date
+        $modified = false;
+        foreach ($replaceHeaders as $name) {
+            if ($validateResponse->hasHeader($name)) {
+                $modified = true;
+                $response->setHeader($name, $validateResponse->getHeader($name));
+            }
+        }
+
+        // Store the updated response in cache
+        if ($modified && $this->canCache->canCacheResponse($response)) {
+            $this->storage->cache($request, $response);
+        }
+
+        return true;
+    }
+}

vendor/guzzle/plugin-cache/Guzzle/Plugin/Cache/DenyRevalidation.php

@@ -0,0 +1,19 @@
+<?php
+
+namespace Guzzle\Plugin\Cache;
+
+use Guzzle\Http\Message\RequestInterface;
+use Guzzle\Http\Message\Response;
+
+/**
+ * Never performs cache revalidation and just assumes the request is invalid
+ */
+class DenyRevalidation extends DefaultRevalidation
+{
+    public function __construct() {}
+
+    public function revalidate(RequestInterface $request, Response $response)
+    {
+        return false;
+    }
+}

vendor/guzzle/plugin-cache/Guzzle/Plugin/Cache/RevalidationInterface.php

@@ -0,0 +1,32 @@
+<?php
+
+namespace Guzzle\Plugin\Cache;
+
+use Guzzle\Http\Message\RequestInterface;
+use Guzzle\Http\Message\Response;
+
+/**
+ * Cache revalidation interface
+ */
+interface RevalidationInterface
+{
+    /**
+     * Performs a cache revalidation
+     *
+     * @param RequestInterface $request    Request to revalidate
+     * @param Response         $response   Response that was received
+     *
+     * @return bool Returns true if the request can be cached
+     */
+    public function revalidate(RequestInterface $request, Response $response);
+
+    /**
+     * Returns true if the response should be revalidated
+     *
+     * @param RequestInterface $request  Request to check
+     * @param Response         $response Response to check
+     *
+     * @return bool
+     */
+    public function shouldRevalidate(RequestInterface $request, Response $response);
+}

vendor/guzzle/plugin-cache/Guzzle/Plugin/Cache/SkipRevalidation.php

@@ -0,0 +1,19 @@
+<?php
+
+namespace Guzzle\Plugin\Cache;
+
+use Guzzle\Http\Message\RequestInterface;
+use Guzzle\Http\Message\Response;
+
+/**
+ * Never performs cache revalidation and just assumes the request is still ok
+ */
+class SkipRevalidation extends DefaultRevalidation
+{
+    public function __construct() {}
+
+    public function revalidate(RequestInterface $request, Response $response)
+    {
+        return true;
+    }
+}

vendor/guzzle/plugin-cache/Guzzle/Plugin/Cache/composer.json

@@ -0,0 +1,28 @@
+{
+    "name": "guzzle/plugin-cache",
+    "description": "Guzzle HTTP cache plugin",
+    "homepage": "http://guzzlephp.org/",
+    "keywords": ["plugin", "guzzle"],
+    "license": "MIT",
+    "authors": [
+        {
+            "name": "Michael Dowling",
+            "email": "mtdowling@gmail.com",
+            "homepage": "https://github.com/mtdowling"
+        }
+    ],
+    "require": {
+        "php": ">=5.3.2",
+        "guzzle/http": "self.version",
+        "guzzle/cache": "self.version"
+    },
+    "autoload": {
+        "psr-0": { "Guzzle\\Plugin\\Cache": "" }
+    },
+    "target-dir": "Guzzle/Plugin/Cache",
+    "extra": {
+        "branch-alias": {
+            "dev-master": "3.7-dev"
+        }
+    }
+}